I. Field
The present disclosure relates generally to electronics, and more specifically to amplifiers.
II. Background
A wireless device (e.g., a cellular phone or a smartphone) in a wireless communication system may transmit and receive data for two-way communication. The wireless device may include a transmitter for data transmission and a receiver for data reception. For data transmission, the transmitter may modulate a radio frequency (RF) carrier signal with data to obtain a modulated signal, amplify the modulated signal to obtain an output RF signal having the proper transmit power level, and transmit the output RF signal via an antenna to a base station. For data reception, the receiver may obtain a received RF signal via the antenna and may amplify and process the received RF signal to recover data sent by the base station.
A wireless device may include amplifiers of different types for different purposes. For example, a wireless device may include a low noise amplifier (LNA) in a receiver, a driver amplifier (DA) and a power amplifier (PA) in a transmitter, and a variable gain amplifier (VGA) in the receiver and/or transmitter. The wireless device may include multiple amplifiers having outputs coupled together, with each amplifier being either enabled to provide an output signal or disabled to provide no output signal. It may be desirable to provide good isolation when an amplifier is disabled in order to mitigate performance degradation due to a leaked signal.